David Seaburg, head of equity sales trading at Cowen and Company, is a big fan of the Dow Jones Transportation Average. About even with the Utilities average, the "Transports" are up 21 percent year-to-date and trouncing the Industrials' gain of 6 percent.

The sector has upside promise, according to Seaburg, because of several fundamentals factors. For railroads he sees strong earnings and tightened capacity. Simultaneously, airlines have increased pricing strength and traffic while also benefiting from lower fuel costs.

"There are so many things pointing to positives within the transports," he said. "You're going to continue to see this group trade really well. … They're trading at highs but I think that there's a lot more room to go here."

The technicals for the Transports are also bullish, according to the chart work of Craig Johnson, senior technical analyst at Piper Jaffray and president of the Market Technicians Association.

"You've been making a series of higher highs and higher lows – and you're at the midpoint of the price channel," Johnson said. "From our perspective, it looks like we still have 20 percent of upside left to go."

And if Johnson's research is correct, that could have very positive implications for the stocks in general.

Looking at what happens whenever a "Dow Trifecta" takes place, "About 82 or 83 percent of the time, you've seen the broader market higher about 13 weeks later with an average return about 3 to 4 percent," Johnson said. "This is a positive sign not only for the Transportation index but also for the entire market itself."

"It's a great sign for the market," he added. "There's more upside to go for the market and we remain secular bulls."